impure variety, occurring in concretions at Menilmontant, near Paris. Other varieties are cacholong,
girasol, hyalite, and geyserite.
Opalesce
(O`pal*esce") v. i. [imp. & p. p. Opalesced ; p. pr. & vb. n. Opalescing ] To give forth a
play of colors, like the opal.
Opalescence
(O`pal*es"cence) n. (Min.) A reflection of a milky or pearly light from the interior of a
mineral, as in the moonstone; the state or quality of being opalescent.
Opalescent
(O`pal*es"cent) a. Reflecting a milky or pearly light from the interior; having an opaline play
of colors.
Opaline
(O"pal*ine) a. [Cf. F. opalin.] Of, pertaining to, or like, opal in appearance; having changeable
colors like those of the opal.
Opalize
(O"pal*ize) v. t. [imp. & p. p. Opalized ; p. pr. & vb. n. Opalizing.] [Cf. F. opaliser.] To
convert into opal, or a substance like opal. Lyell.
Opalotype
(O*pal"o*type) n. [Opal + -type.] (Photog.) A picture taken on "milky" glass.
Opaque
(O*paque") a. [F., fr. L. opacus. Cf. Opacous.]
1. Impervious to the rays of light; not transparent; as, an opaque substance.
2. Obscure; not clear; unintelligible. [Colloq.]
Opaque
(O*paque"), n. That which is opaque; opacity. Young.
Opaqueness
(O*paque"ness), n. The state or quality of being impervious to light; opacity. Dr. H. More.
Ope
(Ope) a. Open. [Poetic] Spenser.
On Sunday heaven's gate stands ope.
Herbert. Ope
(Ope), v. t. & i. To open. [Poetic]
Wilt thou not ope thy heart to know
What rainbows teach and sunsets show?
Emerson. Opeidoscope
(O*pei"do*scope) n. [Gr. voice + form + -scope.] (Physics) An instrument, consisting
of a tube having one end open and the other end covered with a thin flexible membrance to the center
of which is attached a small mirror. It is used for exhibiting upon a screen, by means of rays reflected
from the mirror, the vibratory motions caused by sounds produced at the open end of the tube, as by
speaking or singing into it. A. E. Dolbear.
Opelet
(Ope"let) n. (Zoöl.) A bright-colored European actinian (Anemonia, or Anthea, sulcata); — so
called because it does not retract its tentacles.
Open
(O"pen) a. [AS. open; akin to D. open, OS. opan, G. offan, Icel. opinn, Sw. öppen, Dan. aaben,
and perh. to E. up. Cf. Up, and Ope.]
1. Free of access; not shut up; not closed; affording unobstructed ingress or egress; not impeding or preventing
passage; not locked up or covered over; — applied to passageways; as, an open door, window, road,
etc.; also, to inclosed structures or objects; as, open houses, boxes, baskets, bottles, etc.; also, to means
of communication or approach by water or land; as, an open harbor or roadstead.
Through the gate,
Wide open and unquarded, Satan passed.
Milton
